The loss of motor function due to neurological injury or disease has significant consequences on independence, health, participation in society, and quality of life. Neurological disorders such as stroke, cerebral palsy (CP), spinal cord injury (SCI) and multiple sclerosis (MS) can lead to loss of mobility and significant loss of independence in daily activities. In many of these diseases, the motor system remains intact but cortical control over these functions is lost. One method of restoring function to these individuals is the use of electrical stimulation of the peripheral nerves, known as neuroprostheses, to restore coordinated control of the paralyzed muscles. In order to address the needs of this patient population, a new concept in neuroprostheses has recently been invented and developed at Case Western Reserve University (CWRU). This neuroprosthesis is the ?Networked Neuroprosthesis? (NNP), and uses a modular approach to implanted devices. The NNP system is the first fully implanted modular neuroprosthesis that includes implantation of all power, signal processing, biopotential signal recording, and stimulating components. The modular design of the NNP System allows it to be configured and tailored for the needs of each type of disability and each individual with a disability so that maximum use is made of the individual's remaining voluntary function, with electrically-stimulated function provided as needed. A major milestone of our program that has been achieved is the implantation of the NNP in the first subject. We now seek to advance the technology to impact a broader patient population, improve users to access the technology, and enable the transfer of the technology to the real-world clinical setting. To achieve these goals, our Specific Aims are to 1) enhance the hardware, particularly through improved power management and circuit upgrades; 2) improve software, with a focus on transfer of this technology to multiple sites; 3) build completed systems, and 4) fully test all components in preparation for regulatory approval. All proposed changes will be introduced to the FDA as modifications to the current design, and appropriate regulatory approvals will be sought prior to advancing to clinical trials. At the end of this proposal, we will have completed the full upgrade of the NNP System, greatly expanding clinical indications and usability of the entire system. This work will culminate in the submission of an Early Feasibility IDE for clinical implementation in SCI, establishing a beachhead for future studies.